What are viruses?

With the current situation, our students might have increased some interest in discovering what viruses are. Definitely, they are proof that even the very smallest things can have an outsize impact on the history of life.

There’s no fossil record of viruses in the conventional sense. They’re just too small and fragile to be preserved in rock. But there are fossils of viruses preserved in the DNA of the hosts that they’ve infected. This can help us understand how they evolved with the rest of us. However, the biggest question is ‘are viruses alive’?

The key to the viruses’ success is their simplicity. They consist of a bit of genetic information (DNA or RNA) wrapped in a capsule of protein. They all rely on infecting some sort of host to reproduce and survive. Some scientists think viruses evolved alonside, or even before, the earliest cells.

According to the way they work, experts have to study the genomes of their hosts. Viruses infect a host cell to access the machinery that it uses to replicate its DNA, and then hijack that machinery in order to reproduce. The host cell is forced to manufacture new viruses, which then leave and look for new hosts to infect.

To answer the question of whether viruses are alive, we need to agree on a definition of life: living things carry out NUTRITION, REPRODUCTION and SENSITIVITY. The point is that viruses can’t do them by themselves as long as they need an organism (a host) to survive…

Hopely in a short future many of our students will become important scientifits who will answer what, for now, is a complete mistery.